Q235钢中温无黄烟化学抛光工艺

低碳钢在双氧水系抛光液中化学抛光时,双氧水易分解,温度不易控制,而在硝酸系抛光液中化学抛光会产生黄烟且能耗较大。为此,研制了一种新型无黄烟低碳钢中温化学抛光液对Q235钢化学抛光,考察了化学抛光液组成及温度、时间对抛光质量的影响。结果表明:使用本工艺的化学抛光试样表面平整、粗糙度低,光亮度达3～4级;获得最佳抛光质量的化学抛光工艺为120～250mL/LH3PO4,100～200mL/LH2SO4,40～80g/LNaNO3,10～40g/LNaCl,20g/L复合添加剂,55～65℃,2～5min。     

月球若干地区微波辐射特征研究

中国“嫦娥一号”探月卫星搭载的微波探测仪（Chang’e Lunar Microwave Sounder-CELMS）为认识月球提供了新的视角。利用CELMS的多波段微波遥感数据,研究了月球的微波辐射特征。基于微波辐射传输理论,采用不同时段不同频段微波亮温数据的定量对比、统计分析等方法,首先分析月球微波辐射宏观分布规律及影响因素,在此基础上,重点研究几个区的微波辐射特征,通过从面到点的微波辐射特征研究,为认识月球提供微波辐射特性方面的资料。研究结果显示：月球的微波辐射具有显著的时、空、频差异性;太阳辐射是月球表层及次表层微波辐射的重要影响因素;局部地区微波辐射差异很大,除太阳辐射影响外,与物分、地形、结构等其它因素的相关程度增强。这些微波特征显著不同于光学特征,结合起来,有助于进一步揭示月球的物化性质。     

保持图像亮度的自适应局部对比度增强

目前保持亮度的局部直方图均衡算法用于对比度增强时,大多以亮度均值和中值为图像的亮度分割点,这些方法能较好地保持图像的亮度,但同时也会产生局部过增强。为此提出了一种亮度误差最小的自适应局部对比度增强算法,根据亮度均值绝对误差自适应的选择最佳亮度分割点,然后用保持亮度的双直方图均衡算法对被分割的子图像进行均衡,最后用滤波器消除块效应。实验结果表明,该算法不仅保持了输入图像的亮度,同时也实现了局部对比度增强。     

一种改进的雾天图像复原算法

针对传统暗通道先验算法对大气光亮度值A估算不够准确,图像复原后容易出现天空区域色彩失真这些问题,本文提出一种改进算法.通过设定3个天空阈值筛选出天空区域的像素,然后求其亮度的均值得到大气光亮度值A,剔除白色物体的影响;利用k-means聚类算法对分割天空区域和非天空区域的阈值实现自适应.该算法可以求得更加准确的大气光亮度值A,通过对分割阈值T自适应化,可以更加精确地分割出天空区域,从而可以对天空区域的透射率进行修正,这些改进可以使复原图像的视觉效果更好.仿真实验证明改进算法可以实现预期效果.     

脱墨浆漂白技术

结合脱墨浆的特性,总结了当代废纸脱墨浆漂白技术,介绍了各漂方法的原理、应用及其优缺点,及对脱墨纸浆残余油墨粒子的作用,并对各种漂白方法进行了比较。     

Steven Holl’s NYU Philosophy

The New York University Department of Philosophy, by Steven Holl Architects, combines crisply detailed, rigidly rectangular, black and white elements with odd angles, holey walls and fluctuating rainbows inside a soft, curvaceous old masonry building with Romanesque details. Even though the architect is working on enormous mixed-use projects all over the world now, he took a special interest in creating new facilities for the philosophers close to home despite a constricted site and modest budget. Jayne Merkel describes the striking and rather mysterious new spaces in a small-floorplate, six-storey Victorian-era warehouse in Greenwich Village. Copyright © 2008 John Wiley & Sons, Ltd.     

能见度自动化计算方法

一种新的基于图像边缘处理的能见度自动计算方法被提出。它首先对大气科学中定义的能见度进行简化,接着对地面标记物边界区域提取边缘梯度、对比度、亮度等图像内在特征并针对这些特征利用简化的能见度定义进行计算,最后根据预定义的阈值定量地判定地面预设标志物的可见性从而实现计算能见度。一个能见度自动计算系统模型被建立,通过实验与实际观察结果的数据对比,验证了其算法的可行性和有效性,与已有算法相比其算法在计算的可靠性和有效性方面具有明显改善。     

Perception of brightness when the eyes are closed

To describe the lighting environment during sleep accurately, it is necessary to know the extent to which light is still perceived when the eyelids are closed. In this study, we measured the perception of equivalent brightness under closed-eye and open-eye conditions in binocular photopic vision. The light sources used were monochromatic red (peak wavelength 630 nm), yellow (593 nm), green (515 nm), and blue (460 nm) LEDs, as well as a white LED (T_cp = 4188 K, R_a = 93). A total of 33 subjects (Asian adults aged 22 years on average) with eyelids of approximately the same color were recruited. The average effective transmittances of their closed eyes were 52.4% ± 31.5% for red, 26.2% ± 18.2% for yellow, 21.6% ± 16.7% for green, 4.5% ± 3.9% for blue, and 42.7% ± 24.8% for white light. These values were up to 10 times higher than eyelid transmittances reported previously, so eyelid transmittance cannot by itself explain perceived closed-eye brightness. There were also significant individual differences. As it is unlikely that the physical transmittances of the eyelids differed from subject to subject, psychological factors may be responsible. This phenomenon should be further investigated in the future.     

10 W近衍射极限输出的高效率窄线宽主控振荡放大半导体激光器

为研制近衍射极限的高功率半导体激光器，采用了片上光栅、窄脊型波导、锥形放大器一体集成的主控放大(Master Oscillator Power-Amplifier,MOPA)技术路线，以长度为8 mm、脊型宽度为3μm的波导为单模种子源，配合长度为7 mm、全角为3.3°的锥形放大器，实现了功率10.3 W、慢轴光束质量M²(1/e²)因子=1.06,3 d B线宽40 pm，工作电光效率50.5%的半导体激光输出，并采用片上电致加热光栅调谐技术，实现了中心波长在4 nm范围内连续可调。     

Pupil size estimation model based on luminance and chromaticity spatial distribution

As an important index in studies on vision and display technology, pupil size controls the amount of the light entering human eye. Eye tracking systems are normally used to measure the pupil size while a pupil size estimation model can be applied when actual measurement is not available. The weighting functions of the reported pupil size estimation models show radial symmetry, which contradicted the radial asymmetric distribution of photoreceptors on the retina. Chromaticity spatial distribution has not been taken into consideration either. In this paper, the perceptual experiments are carried out with patterned and colored stimuli to evaluate the spatial and color varying effect of luminance to the pupil. A revised corneal flux density is proposed, which shows a high correlation with pupil diameters. Based on this, a pupil size estimation model is proposed. Pupil diameters can be calculated after inputting luminance and chromaticity spatial distribution matrixes. After verification, this model can be applied to indoor scenes with different lighting temperatures within the general illumination range. This model should be useful in scientific and practical applications where pupil diameter matters.